Apparatus for making sheet glass



Nov. 19, 1935. K. G. KUTCHKA` APPARATUS FOR MAKING SHEET GLASS Filed Feb. ,16, 1955 3 Sheets-Sheet 1 Nov. 19, 1935.

` APPARATUS FOR MAKING SHEET GLASS K. V 5. KuTcHKA 2,021,186

KAWQL G- KUTcHK/-v A TTORNEYS.-

Patented Nov. 19, 1935 UNITED STATES PATENT OFFICE Karl G. Kutchka, Wilkinsburg, Pa., assigner to Pittsburgh Plate Glass Company, a. corporation of Pennsylvania Application February 16, 1935, Serial No. 6,850

6 Claims.

The invention relates to apparatus for making sheet glass and particularly to the construction.

in the forehearth or kiln from which the sheet is drawn. In apparatus of this kind, difculty is experienced in maintaining the bath from which the sheet is drawn of the same temperature on both sides of the line of draw, the normal tendency being-to run ahigher temperature on the side of the line of draw which is nearest the melting tank. This variation in temperature on the two sides of the line of draw tends to cause warping and breakage in the sheet produced, and the present invention has for its principal object the provision of improved clay work (or its equivalent refractory) which will insure the same temperature in the bath on the two sides of the sheet drawn. A further object is to provide an improved arrangement for securing a circulation of the excess glass supplied to the draw pot or receptacle back into the main body of glass in the kiln beneath the receptacle. One embodiment of the invention is illustrated in the accompanying drawings, wherein:

Figure 1 is a vertical section through the tank construction on the line I-I of Fig. 2. Fig. 2 is a horizontal section on the line II--II of Fig. 1. Fig. 3 is a vertical section on the line III-III of Fig. l. And Figs. 4 and 5 are sections respectively on the lines IV-IV and V-V of Fig. 1.

Referring to the drawings, I is a drawing kiln which communicates at its left hand end with a melting tank of the regenerator type. The drawing kiln has the end wall 3, the side walls 4, 4 and a cover consisting of the refractory members 5, 6, 8, 8, and 9, the members 8, 8 each being in the form of an L-block with a drawing opening I0 therebetween, through which the glass sheet I I is drawn continuously. Any form of drawing apparatus may be employed,.the one shown being of the Fourcault type comprising the casing I2 and the pairs of drawing rolls I3, I3 which are driven and apply the necessary traction to the glass sheet.

Extending downward from the cover of the kiln or forehearth to a substantial distance into the body of glass therein is a vertical division wall I4, which extends from one side of the tank to the other. Extending from this vertical division wall I4 to the end wall 3 of the tank is a horizontal division wall I5, such wall extending from one side wall of the kiln to the other, as indicated in Figs. 3 and 4. This division wall is provided with a slot It which lies beneath theline of draw of the sheet I I and serves to supply the glass which goes into the sheet. The division wall is also provided with a pair of anges I'I and I8 extending from one side wall of the tank to the other and dividing the space above the division wall I5 into three receptacles I9, 20, and 2|, the central one of which constitutes the draw pot of the appa- 5 ratus. Located in this draw pot beneath the line of draw of the sheet II is the draw bar 22, whose upper surface lies below the surface of the glass in the pot. The upper edges of the flanges I'I and I8 also lie below the surface of the glass so 10 that in operation any excess glass supplied to the draw pot through the slot I6 which does not go into the formation of the sheet ows over the tops of the anges and into the receptacles I9 and 2I. Burner openings 23, 24, and 24a are 15 provided above the receptacles I9 and 2| to permit of the application of heat so that the body of glass on each side of the sheet II may be maintained. at the same temperature.

In `order to permit of a return of the glass in 2oz` the receptacles IB and 2| to the main body of glass in the kiln, the four circulation ports 25, .25 and 26, 26 are provided, such ports being located at the corners of the horizontal division wall I5,

as indicated in Figs. 2, 3, and 4. In or-der to pro- 25 mote the flow of glass in the receptacles to the circulation ports, the bottoms thereof are inclined as indicated at 21 in Fig. 3 and at 28 in Fig. 4.

The arrangement of clay work as above de- 301* scribed tends to give a uniform temperature in the body of glass from which the sheet is drawn on each side of the line of draw. The glass which goes `into the formation of the sheet flows up `through the slot I6 to the surface of the bath 35 from which it is drawn into the sheet. The excess glass flowing into the pot passes over the upper edges of the anges I1 and I8, as indicated by the arrows, into the receptacles I9 and 2|, and as it becomes cooled in these receptacles, flows down- 40 ward through the circulation ports 25 and 2B to the body of glass beneath the division wall I5, where it tends to circulate back along the bottom of the forehearth and melting tank, as indicated by the arrows in Fig. l. The burners 23 and 24 come into play in keeping the temperature of the glass in the draw pot at the point best suited. for the drawing operation and for equalizing'the temperature of the two sides of the line of draw in case some slight departure from uniform `temperature should occur. The burners are also used when the drawing operation is discontinuedfor reconditioning the bath preliminary to initiating a further drawing operation. 56

What I claim is:

1.Y In combination in glass drawingapparatus comprising a drawing kilnV adapted to carry a body of molten glass and a sheet drawing means above the bath, Va cover for the kiln having a transverse drawing opening therethrough, an upright division wall lying transversely of the kiln intermediate its ends, and extending downwardly from the cover to a point below the glass level, a horizontal division wall below the glass level extending from the upright division wall to the rear end wall of the Vkiln and from one side wall of the kiln to the other and provided with a slot directly below said drawing opening, and a ange projecting upward from the horizontal division wall on each side of the slot to a point Y below the glass level, and dividing the space above saidV horizontal division wall into three parallel receptacles extending from one side of the kiln to the Yother the central one of which constitutes a drawpot with its center between said drawing opening and ysaidrslot in vertical alignment therewith. Y Y

2. InV combination in glass drawing apparatus comprising a drawing kiln adapted to carry a body of molten glass anda sheet drawing means above the bath, a cover for the kiln having a transverse drawing opening therethrough, an upright division wall lyingtransversely of the kiln intermediate its ends, and extending downwardly from the cover to a point below the glass level, a horizontal division wall below the glass level extending from the upright division wall to the rear end wall of the kiln and from one side wall of the kiln to the other, and provided with a slot directly below said drawing opening, a flange projecting upward from the horizontal division wall on each side of the slot to a point below the glass level, and dividing the space above said horizontal division wall into'three parallel receptacles extending from one sideY of the kiln to theother, the central one of `which constitutes'a draw'pot with its center in vertical alignment with the drawing opening and said slot, and a draw bar Vin Ythe pot between the drawing opening and said slot. Y

3. In combination in glass drawing apparatus comprising a drawing kiln adapted to carry a body of molten glass and a sheet drawing means above the bath, a cover for the kiln having a transverse drawing openingV therethrough, an upright division wall lying transversely of the kiln intermediate its ends, and extending downwardly' from the cover toV a point below the4 glass level,

`a horizontal division wall below the V,glass level extending from the upright division vwall to the rear end wall of the kiln and from'one side wall of the kiln to the other, and provided with a slot directly below said drawing opening, and a `flange projecting upward from the horizontal division wall on each side of the slot to a point belowthe glass `level and dividing the space aboveV said horizontal division wall into three parallel receptacles extending from one side ofthe kiln to the other, the central one of whichconstitutesA a draw pot with its center between said drawing opening and said slot in vertical alignment therewith,V circulation ports being provided through the bottom walls of each of the receptacles between which the draw pot is located.

4. In combination in glass drawing apparatusv comprising a drawing kiln adapted to carry a body owfmolten glass and asheet drawing means above the bath, a cover Vfor the kiln Vhaving a,Y transverse drawing opening therethrough,V an upright division wall Ylying transversely of the kiln intermediate its ends and extending downwardly from the cover toa pointbelow the glass 5 receptacles extending from one side ofthe kiln l5 to the other, the central one of which constitutes a draw pot with its center between said drawing opening and said slot in vertical alignment therewith, said horizontal division wall being cut away at its four corners to between the receptacles thereabove` and the body Y of glass in the kiln therebeneath. Y

5. In combination'in glass drawing apparatusV comprising a drawing kiln adaptedV to carry `4`a' body of molten glass and a sheet drawing Vmeansr25'Y above the bath, aV cover for the kiln having a transverse drawing opening therethrough, an

uprightl division wall lyingV transversely of the kiln intermediate its ends, and extending downwardly from the cover to a point-below the glass 30 level, a horizontal division wall below the glass level extending fromV the upright division wall to the rear end wall of the kiln and from one side wall of the kiln to the other, and provided with a slot directly below said drawing opening, and a 35 flange projecting upward from the horizontal division wall on each-side of the slot to a point below the glass level and dividing the space above` said horizontal division wall Vinto threeV parallel receptacles extending from one side ofthe kiln to l0` the other, the central one ofwhich constitutes a draw pot Ywith its center between said Vdrawing opening and said slot in vertical alignment therewith, the bottom walls of the receptacles lying on either side of the draw potbeing inclined downy45 ward from their middle portions to their ends, and ports being provided at such ends vaffording communication between the receptacles and the kiln therebeneathl 6. In combination in glass drawing apparatus 50 f comprising a drawing kiln adapted to carrya body of molten glass and asheet drawing means Y above the bath, a cover for the kiln having a transverse drawing opening therethrough, an

upright division wall lying transversely of the 55 Y kiln intermediate its ends, andextending downwardly from the cover to a point below the glass level, a horizontal division wall below the glass level extending from the-upright division wall to the rear end wall of the kiln and from one side 6.0 wall of the kiln to the other, and provided with a slotfdirectly below said drawing openingfa flangeV projecting upward from `the horizontal division wall 0n each'side of the slot to a point below the 1 glass level,'and dividing the spaceabove said'hor- 05 izontal division wall into three parallel receptacles i extending from one side of the kiln to the other, 'f the'central one of which constitutes a draw pot n with its center in vertical alignment with theV drawing opening and said slot, and means for V ,heating the 'space above each of the receptacles provide'circulation ports 20 Y 

